1. Field of the Invention
This invention relates to a system and method of sealing leaks in process piping and equipment without shutdown by providing a clamp having a cavity surrounding a leaking structure, sealant equipment comprising an injection gun to inject a sealant into the clamp cavity, means for pressuring moldable sealant from the gun into the clamp cavity in a staged manner beginning at a point away from the leak site. The preferred sealant comprises a moldable nitrile rubber delayed curing (vulcanizing) formulation or composition molded into shapes for insertion into an injection gun.
2. Discussion of prior art
There exist needs for effective and efficient methods for repairing leaks in industrial piping and equipment without having to stop the process flow or operation. Especially needed are methods that will perform well with all kinds of industrial media and under adverse conditions. Industrial leaks frequently result in emergencies due to the toxic or explosive nature of the leaks, damage to surrounding equipment and danger to operating personnel. To address these needs on-line leak sealing technology is widely used in companies with continual producing process, where unexpected leaks may cause an emergent shutdown and loss time and expense. With on-line leak sealing technology, leaks, which are normally found at flanges, tees, elbows, valves, pipelines, and other welded joints need to be stopped quickly and efficiently without affecting the process. But it is often extremely difficult to seal off a pipe leak in the field and particularly difficult to do so without modification of the piping and/or equipment or discontinuing the flow of leaking medium. Thus the economic benefits of an on-line leak sealing technology that is effective in industrial operations are many and significant. By solving the leaking problem while keeping an industrial plant on-line, processing plant are saved from costly unscheduled shutdown, environmental damage, unsafe and hazardous condition resulting from the leaks. Instead of replacing leaking equipment with a new one, an expensive and time-consuming solution, on-line leak sealing technology allows repair of equipment while maintaining system integrity, extending the life of the equipment components. It also protects the environment from noise and harmful emissions and avoids explosion caused by leaking combustible media.
Many commercial pipe leak sealing systems utilize fiberglass wraps with two part epoxy systems and frequently cannot be used without shutting off process media flow to suspend the leak while repairs are made. Some commercial leak repair systems require the application (injection) of two part sealants and often with mixtures of catalysts, fillers and the like. Other repair systems use special enclosures for the leaking pipe section (or equipment section) into which is injected epoxy or two part elastomeric sealants. These two part sealant systems are not totally satisfactory. Moreover, many leaking system are in pipe or equipment at high pressure and temperature and contain chemicals and/or other medium that destroy or weaken conventional sealants. It would be very beneficial to have an easily implemented method of on-line process leak repair that is easily deployed, efficient and effective utilizing easily stored leak sealant formulation which, when applied, would become vulcanized, hardened and stabilized during application. The present invention provides such a method.